<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace lemon\bootstrap4;

use Yii;
use yii\base\InvalidConfigException;
use yii\helpers\ArrayHelper;
use yii\bootstrap4\Html;

/**
 * Breadcrumbs represents a bootstrap 4 version of [[\yii\widgets\Breadcrumbs]]. It displays
 * a list of links indicating the position of the current page in the whole site hierarchy.
 *
 * To use Breadcrumbs, you need to configure its [[links]] property, which specifies the links to be displayed. For example,
 *
 * ```php
 * echo Breadcrumbs::widget([
 *	 'links' => isset($this->params['breadcrumbs']) ? $this->params['breadcrumbs'] : [],
 *	 'options' => [],
 * ]);
 * ```
 * @see http://getbootstrap.com/javascript/#buttons
 * @author Alexandr Kozhevnikov <onmotion1@gmail.com>
 * @author Simon Karlen <simi.albi@outlook.com>
 */
class Breadcrumbs extends Widget
{
	/**
	 * @var string the name of the breadcrumb container tag.
	 */
	public $tag = 'ol';
	/**
	 * @var bool whether to HTML-encode the link labels.
	 */
	public $encodeLabels = true;
	/**
	 * @var array the first hyperlink in the breadcrumbs (called home link).
	 * Please refer to [[links]] on the format of the link.
	 * If this property is not set, it will default to a link pointing to [[\yii\web\Application::homeUrl]]
	 * with the label 'Home'. If this property is false, the home link will not be rendered.
	 */
	public $homeLink;
	/**
	 * @var array list of links to appear in the breadcrumbs. If this property is empty,
	 * the widget will not render anything. Each array element represents a single link in the breadcrumbs
	 * with the following structure:
	 *
	 * ```php
	 * [
	 *	 'label' => 'label of the link',  // required
	 *	 'url' => 'url of the link',	  // optional, will be processed by Url::to()
	 *	 'template' => 'own template of the item', // optional, if not set $this->itemTemplate will be used
	 * ]
	 * ```
	 *
	 *
	 */
	public $links = [];
	/**
	 * @var string the template used to render each inactive item in the breadcrumbs. The token `{link}`
	 * will be replaced with the actual HTML link for each inactive item.
	 */
	public $itemTemplate = "<li class=\"breadcrumb-item\">{link}</li>\n";
	/**
	 * @var string the template used to render each active item in the breadcrumbs. The token `{link}`
	 * will be replaced with the actual HTML link for each active item.
	 */
	public $activeItemTemplate = "<li class=\"breadcrumb-item active\" aria-current=\"page\">{link}</li>\n";
	/**
	 * @var array the HTML attributes for the widgets nav container tag.
	 * @see \yii\helpers\Html::renderTagAttributes() for details on how attributes are being rendered.
	 */
	public $navOptions = ['aria-label' => 'breadcrumb'];


	/**
	 * Initializes the widget.
	 * If you override this method, make sure you call the parent implementation first.
	 */
	public function init()
	{
		parent::init();
		$this->clientOptions = false;
		Html::addCssClass($this->options, ['widget' => 'breadcrumb']);
	}

	/**
	 * Renders the widget.
	 * @throws InvalidConfigException
	 */
	public function run()
	{
		$this->registerPlugin('breadcrumb');

		if (empty($this->links)) {
			return '';
		}
		$links = [];
		if ($this->homeLink === null) {
			$links[] = $this->renderItem([
				'label' => Yii::t('yii', 'Home'),
				'url' => Yii::$app->homeUrl,
			], $this->itemTemplate);
		} elseif ($this->homeLink !== false) {
			$links[] = $this->renderItem($this->homeLink, $this->itemTemplate);
		}
		foreach ($this->links as $link) {
			if (!is_array($link)) {
				$link = ['label' => $link];
			}
			$links[] = $this->renderItem($link, isset($link['url']) ? $this->itemTemplate : $this->activeItemTemplate);
		}
		return Html::tag('nav', Html::tag($this->tag, implode('', $links), $this->options), $this->navOptions);
	}

	/**
	 * Renders a single breadcrumb item.
	 * @param array $link the link to be rendered. It must contain the "label" element. The "url" element is optional.
	 * @param string $template the template to be used to rendered the link. The token "{link}" will be replaced by the link.
	 * @return string the rendering result
	 * @throws InvalidConfigException if `$link` does not have "label" element.
	 */
	protected function renderItem($link, $template)
	{
		$encodeLabel = ArrayHelper::remove($link, 'encode', $this->encodeLabels);
		if (array_key_exists('label', $link)) {
			$label = $encodeLabel ? Html::encode($link['label']) : $link['label'];
		} else {
			throw new InvalidConfigException('The "label" element is required for each link.');
		}
		if (isset($link['template'])) {
			$template = $link['template'];
		}
		if (isset($link['url'])) {
			$options = $link;
			unset($options['template'], $options['label'], $options['url']);
			$link = Html::a($label, $link['url'], $options);
		} else {
			$link = $label;
		}

		return strtr($template, ['{link}' => $link]);
	}
}
